Your Digest for Sunday, Mar 24, 2024 07:59 PM


SurfactantProteins.pngSource

Causes of hemidiaphragmatic elevation

[!INFO] From radiopaedia
causesOfDiaphragmaticEventration.png


The fibers transmitting visual information from the superior retina remain superior in the chiasm; those from the inferior retina remain inferiorly situated. Approximately 90% of chiasmal fibers originate from the macula, and, of these, those that cross lie superiorly and posteriorly within the chiasm.
Source
opticChiasmAnatomy.png
junctionalScotoma.pngSource

junctionalScotoma-1.png
Source


Q 7: Craniopharyngioma

RathkesPouch.png


  1. CRH stimulation test - differentiates Cushing's disease from all other causes of hypercortisolism


Folate and B12 metabolism

[[DNAFolateB12Deficiency.png]]
FolateAndB12Metabolism.png
Source

[!INFO] Key points:

  1. The synthesis of methionine from homocysteine is catalyzed by methionine synthase, an enzyme that requires not only folate (as 5-methyltetrahydrofolate) but also vitamin B12.
  2. 3 vitamins are interlinked : B12, B9 and B6
  3. Thus, the concentration of homocysteine in the blood is regulated by three B-vitamins: folate, vitamin B12, and vitamin B6

b12deficiencySketch.jpg
| Folate | B12 |
| :--------------------------------------------------------------------------------------------------------------: | :-------------------------------------------------------------------------------------------------------------------------: |
| green leaves (mnemonic: folate = foliage) | Animal sources |
| 4 months of stores | 2 years of stores |
| large percentage destroyed in cooking | Only little destroyed in cooking |
| Absorption is mainly in the duodenum and jejunum Source | Terminal ileum by receptor mediated endocytosis. Source |


Presentation

Labs:

Management


Urea is elevated in acute dehydration.
Mechanism: Source

[!INFO] Shortcuts


BloodBrainbarrierSchematic.png


Side effects of Erythropoietin treatment:

There are a number of reasons why patients may fail to respond to erythropoietin therapy:



betablockerPhamacokinetics.png


[!INFO] Mnemonic:
Poor penetration : BAT CAVE (deep dark corners = poor penetrance)
PoorCNCPenetranceMnemonicBatCave.png

Cephalosporins:


opioid and morphine's have O. Therefore, myosis, not mydriasis
OpioidMorphineMnemonic.png
| Toxin | Antidote | |
| --------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------ |
| Acetaminophen | N-Acetylcysteine | |
| Anticholinergics | Physostigmine* | |
| Anticoagulants, oral factor Xa inhibitors (apixaban, edoxaban, rivaroxaban) | Andexanet alfa | |
| Benzodiazepines | Flumazenil* | |
| Black widow spider bite | Lactrodectus antivenom | |
| Botulism | Botulinum antitoxin | |
| Beta-blockers | Glucagon, IV lipid emulsion | |
| Calcium channel blockers | Calcium
IV insulin in high doses with IV glucose
IV lipid emulsion | |
| Carbamates | Atropine Pralidoxime chloride | |
| Crotaline snake bites (US) | Crotalinae polyvalent immune Fab (ovine) | |
| Cyanide | Hydroxocobalamin Cyanide antidote kit (includes amyl nitrate, sodium nitrite, and sodium thiosulfate) | Vit B12 forms cyanocobalamin which restores mitochondrial function |
| Dabigatran | Idarucizumab | |
| Digitalis glycosides (eg, digoxin, digitoxin, oleander, foxglove) | Digoxin-specific Fab fragments | Fab = Antigen binding fragments |
| Ethylene glycol | Fomepizole Ethanol | [[2021 General Medicine July#Methanol poisoning]] (alcohol dehydrogenase inhibitor) |
| Heavy metals | Chelating drugs (see table Guidelines for Chelation Therapy) | heavy metals: Dimercaprol (aka British anti-lewisite)
Cobalt, Pb, Zn : Edetate calcium sodium
Au,Pb,AS : Penicillamine
Succimer |
| Ionizing radiation | Potassium iodide | |
| Iron | Deferoxamine | |
| [[Tuberculosis#Isoniazid|Isoniazid]] | Pyridoxine (vitamin B6) | Pyridoxine (B6) |
| Methanol | Fomepizole Ethanol | Prevents formation of glycolic acid and glycloxylic acid by alcohol dehydrogenase. |
| Methemoglobin-forming agents (eg, aniline dyes, some local anesthetics, nitrates, nitrites, phenacetin, sulfonamides, dapsone). | Methylene blue
Exchange transfusion
Hyperbaric oxygen
| Hb has Fe3+ instead of 2+. (poor O2 capacity).
Blue Skin.
Dark blood. |
| Methotrexate | Leucovorin (folinic acid) Glucarpidase (carboxypeptidase-G2) | |
| Opioids | Naloxone | |
| Organophosphates | Atropine, Pralidoxime | See above |
| Scorpion envenomation (Centruroides sp) | Centruroides immune F(ab’)2 | |
| Sulfonylurea | Octreotide | Somatostatin analog; prevents calcium entry into beta cells -> inhibits insulin release. Prevents rebound hypoglycemia in sulfonylurea overdose. |
| Thallium | Prussian blue | |
| Tricyclic antidepressants | Sodium bicarbonate | |
| Unfractionated heparin | Protamine | |
| Valproic acid | L-Carnitine† | |
| Warfarin | Vitamin K
Fresh frozen plasma Prothrombin complex concentrate (PCC) | |


WilsonsDiseaseDystonia.png
#2021BSQ-NOV/Q54
Aporecaeruloplasmin + 6 Cu atoms = ceruloplasmin (the major circulating form of Copper)

Mutations in ATP7B in Wilson disease impairs both the incorporation of copper into apoceruloplasmin and the excretion of copper into bile.

[!TIP] Eyes and basal ganglia and of course liver


AntiviralsSpectrum.png

Source
Foscarnet and cidofovir are toxic.

Source

homocystinuriaAppearance.png
See [[Anaemia#Folate and B12 metabolism]]
FolateAndB12Metabolism.png